Synthesis of Self-assembling Carbon Nanotube-Polyaniline Nanocomposite on a Flexible Graphene-coated Substrate for Electrochemical Electrode Applications

Multi-wall carbon nanotube/polyaniline (CNT/PANI) nanocomposite thin films for electrochemical electrode applications are synthesized on flexible graphene-coated indium-tin-oxide (ITO) substrates by using a drop-casting technique. Graphene serves as an adhesion layer between the CNT/PANI nanocomposite film and the flexible ITO substrate. A nanoscale vermicular morphology of PANI films containing well-dispersed CNTs is formed on the surface of graphene. The electrochemical characteristics of the nanocomposite films are investigated in a 0.5-M LiClO4 + PC electrolyte. The electrical conduction of the CNT/PANI/graphene/ITO film is considerably superior to that of a PANI/ITO film. The cyclic voltammogram measurements indicate that the specific capacitance of the CNT/PANI film is ∼134 F/g which is ∼11% higher than that (∼120 F/g) of the pure PANI film. Most importantly, the nominal capacitance loss of the PANI/CNT film (∼1.2%) is significantly improved relative to that of the pure PANI film (∼18.1%) after 100 charge-discharge cycles. We attribute the considerably improved capacity retention of the flexible CNT/PANI electrode to the graphene adhesion layer.